Dying yew shrub
We have had this yew border growing for at least 8 years. It was growing fine, until the last two years. All of a sudden the shrub is yellowing and dying. We pulled out one of the shrubs, as you can see the gap, but now it seems to be moving to the next shrub. When we pulled the dying shrub out, the roots looked fine, no disease or root rot. From the picture, you can see how it is moving down the row. Please give advice on what to do to stop the advancement of whatever it is that might be killing the shrubs. It comes on very fast....the new one that is dying, was perfectly fine a month ago and growing new growth, and then all of a sudden it has turned lifeless. Thanks.
Your yew looks like it has a root issue. Yews hate "wet feet", i.e. poor drainage, over-mulching, and compacted soil, which keeps the soil too wet. Wet feet leads to root rots.
Pull back the mulch. Keep it thin--no more that 2-3" deep. Mulch should never be piled up around trunks of any plants. Keep it back a few inches always.
With all the rain this spring, plus cool weather so there was little evaporation of water in the soil, the soil may be too wet in this location now. We had a similar weather condition last spring through summer, which may account for the loss of one yew last year.
Try to improve drainage. (You may want to dig a hole, fill it with water, and watch to see how long it takes to drain.) If the grade of your lot has changed over the years, it may be making the soil wetter.
If the yew you dug up last year had whitish roots, not dark rotted roots, then perhaps the roots were alive and the yew may have regenerated if the dead top growth was cut back. Before you tackle the yew, be sure the top growth is really dead by scratching the bark and looking for green underneath. Green would indicate the wood is still alive.